This invention relates to a metering flume for use in fluid flow metering applications and more particularly to such a metering flume for placement in an exit conduit in the bottom of a sewer well.
Accurate measurement of a fluid flow in a flow conduit usually requires installation of a weir or flume together with a device which detects the surface level of the flow ahead of the weir or flume and then converts the surface level to rate of flow. Such an installation requires considerable labor and involves temporarily blocking the flow upstream of the installation, placing the weir or flume in the flow path, sealing it in place and removing the upstream block prior to finally installing the surface detection device. Obtaining an adequate seal of the weir or flume into the invert of the flow path is sometimes complicated. For example, when the installation is to be made in the bottom of a sewer well or manhole, the invert is generally rough and irregular. When a weir is used further complications arise by the large upstream back-up due to the large head drop required at the weir and by silt collection which occurs ahead of the weir. Sealing a flume in the rough and irregular bottom of a manhole is even more difficult. An assembly containing an integral weir or flume is desirable which is easily and quickly sealed in the flow path through the bottom of a sewer well.